obama administration says it's worked out most of the bugs from healthcare.gov but w more work is needed on the troubled insurance website. >>> and drone drop-off? amazon unveils its futuristic plan to deliver your purchase to your doorstep in under an hour. captioning funded by cbs this is the "cbs morning news" for ay, de >>> this is the "cbs morning news" for monday, december 2nd, 2013. good morning. good to be with you. i'm anne-marie green. well, federal transportation officials have begun their investigation into the deadly crash of a new york city commuter train. at least four people were killed and more than 60 others injured. the metro north train was on its way from poughkeepsie to manhattan when it jumped the tracks as it rounded a curve yesterday morning. investigators are now looking into the train's speed, possible mechanical issue, and human error. marlie hall is at the crash site. marlie, good morning. >> reporter: good morning, anne-marie. federal investigators continue to pore over this crash site this morning trying to determine what led to that deadly train derailment